Cotton is an important economic crop and is a main raw material in textile industry. For a long period, yield and quality of cotton fiber have always been two important goals of cotton breeding improvement. Upland cotton (Gossypium hirsutum L.) accounts for about 90% of the world's current total cotton production due to its high yield and wide adaptability (Zhang et al. 2015: Sequencing of allotetraploid cotton (Gossypium hirsutum L. acc. TM-1) provides a resource for fiber improvement. Nat Biotechnol 33:531-537). However, since the fiber quality of the upland cotton is still not ideal enough to meet the requirements of rapid development of modern textile technology, while the genome of Sea-Island cotton (G. barbadense L) contains excellent fiber genes (Liu et al. 2015: Gossypium barbadense genome sequence provides insight into the evolution of extra-long staple fiber and specialized metabolites. Sci Rep 5:14139; Wang et al. 2013: Genetic dissection of the introgressive genomic components from Gossypium barbadense L. that contribute to improved fiber quality in Gossypium hirsutum L. Molecular Breeding 32:547-562; Yuan et al. 2015: The genome sequence of Sea-Island cotton (Gossypium barbadense) provides insights into the allopolyploidization and development of superior spinnable fibres. Sci Rep 5:17662), it has always been a goal pursued by breeders how to introduce the excellent genes into the upland cotton which has high yield and wide adaptability, to improve the fiber quality of the upland cotton. However, due to reproductive isolation existed in interspecific crossing or severe segregation distortion in cross offspring, it is very difficult to directly use these excellent genetic resources for breeding, which is also an important reason why the improvement of upland cotton fiber quality has always been stagnant.
Accordingly, it would be desirable to improve cotton molecular breeding methods to address these and other drawbacks in the known art.